1. Technical Field
The invention of the present application relates to a luminous or fluorescent artificial stone composition. More specifically, the invention of the present application relates to an artificial stone composition which has a night decorativeness, a luminousness, such as a luminescence and a light-emitting property, accompanied by ultraviolet absorption and which is useful in a building material or a sight material as a direction indicator or a position guide using light in dark surroundings.
2. Description of Prior Art
An artificial stone obtained by pulverizing a natural stone and mixing the pulverizate with a resin or the like for solidification is known. Regarding this artificial stone, various attempts have been made to provide a product having a design with a tone of a natural stone, such as marble, granite or the like, and having an excellent hardness and strength.
As an approach to improve properties and a performance of such an artificial stone, there has been also a proposal of imparting a light function using a luminous material, such as a luminescent material or a fluorescent material such as an ultraviolet light-emitting material which emits light through ultraviolet absorption. This approach is conducted by mixing a fluorescent material with a resin component as a binder of an artificial stone for solidification or by mixing a luminescent fluorescent material, such as strontium aluminate or the like, or a ultraviolet fluorescent material with an ubsatuarated polyester, a methacrylic resin, a glass or the like for solidification, pulverizing the mixture, and using the resulting product as an aggregate to form an artificial stone.
However, in the case of the conventional luminous or fluorescent artificial stone, there were defects that in either of the above-mentioned methods, it is only in the position where the binder resin component or the aggregate exposed to the surface of the artificial stone is arranged that the luminescent material or the like acts and the luminescent material or the like contained in the artificial stone molded product does not act at all. A luminous material, such as a luminescent material or the like, is quite expensive, and even the addition of the same in a small amount increases an overall cost to from 3 to 10 times. Accordingly, an ordinary artificial stone containing therein a luminous material free from this function was not practical in view of the cost. Further, light was emitted only in the surface layer of the artificial stone, so that light emitted does not have a thickness. Thus, there is a problem that the use thereof was quite limited because of such a high cost and the limited luminousness.
Meanwhile, when the amount thereof is controlled for decreasing the cost, there occurs such an inconvenience that the luminous or luminescent functional effect is scarcely provided.
Accordingly, the realization of a new artificial stone which is obtained with the use of a luminous or fluorescent material, such as a luminescent material or the like, in a lesser amount for decreasing the cost to improve a light function of an artificial stone, which is excellent in the functional effect, and which can fully provide a thickness of light emitted in not only the surface but also the whole of the artificial stone, has been in demand.